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In this paper we present a search algorithm that finds useful optical quantum states which can be created with current technology. We apply the algorithm to the field of quantum metrology with the goal of finding states that can measure a phase shift to a high precision. Our algorithm efficiently produces a number of novel solutions: we find experimentally ready schemes to produce states that show significant improvements over the state-of-the-art, and can measure with a precision that beats the shot noise limit by over a factor of 4. Furthermore, these states demonstrate a robustness to moderate/high photon losses, and we present a conceptually simple measurement scheme that saturates the Cramér–Rao bound.

in many applications of quantum information required a precise engineering the quantum state the system this

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essential to applications such as quantum metrology and

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quantum computing and fundamental quantum

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experiments here we think someone's mythology

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Our task is to measure phase difference between

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2 parts in and from is known the

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quantum states for the large quantum fish information could measure phase shift to a high precision it is

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therefore the goal of this work fine quantum states

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side with a large quantum this information effects on optical states that can made with current technology so how come we engineer quantum

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states have a large quantum vision mission state

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engineering scheme we consider shown here firstly to inverse states such as phosphates and squeeze states by impotence detailed optical comments the teammates then passed through a number of operators such as beam splitters and displays operators finally heralding measurements performed such effects on an extension or cottage measurement this heralds the final state and then assess the state to see whether it has a large quantum pitch information the heart which choose the inverse stays operators and how the measurement in this work work we use a search algorithm for this task the algorithm searches the different combinations of Interstates operators and how the measurements the algorithm then uses the quantum fish information as a fitness function defined quantum states the useful for quantum theory the algorithm

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proved to be highly effective and efficient found a number of quantum states that improved over previous schemes using this technique we found states which can measure phase shift to a precision over 4 times better than some Muslim this amounts to reach 6 improvement in the state of the art in optical quantum charity furthermore the state's somebody oven reverse to medium to high losses and crucially they can all be made with current technology we therefore expect an experiment confirmed these results in the near future